Morphological changes and transversal growth kinetics along the apical meristem in the pericycle cell types of the onion adventitious root

PROTOPLASMA ◽  
1991 ◽  
Vol 160 (2-3) ◽  
pp. 108-114 ◽  
Author(s):  
C. Garc�a-S�nchez ◽  
P. J. Casero ◽  
P. G. Lloret ◽  
J. Navascu�s
Keyword(s):  
Growth Kinetics ◽  
Adventitious Root ◽  
Apical Meristem ◽  
Morphological Changes ◽  
Cell Types ◽  
Pericycle Cell

Growth kinetics in the pericycle cell types along the apical meristem of the onion root

1990 ◽  
Vol 14 ◽  
pp. 101
Author(s):  
P CASERO ◽  
C GARCIASANCHEZ ◽  
P LLORET ◽  
J NAVASCUES
Keyword(s):  
Growth Kinetics ◽  
Apical Meristem ◽  
Cell Types ◽  
Onion Root ◽  
Pericycle Cell

Changes in cell length and mitotic index in vascular pattern-related pericycle cell types along the apical meristem and elongation zone of the onion root

PROTOPLASMA ◽  
1989 ◽  
Vol 153 (1-2) ◽  
pp. 85-90 ◽  
Author(s):  
P. J. Casero ◽  
C. Garc�a-S�nchez ◽  
P. G. Lloret ◽  
J. Navascu�s
Keyword(s):  
Mitotic Index ◽  
Apical Meristem ◽  
Cell Types ◽  
Cell Length ◽  
Vascular Pattern ◽  
Elongation Zone ◽  
Onion Root ◽  
Pericycle Cell

Ultrastructural Study of a differentiating human colon carcinoma cell line

1990 ◽  
Vol 48 (3) ◽  
pp. 208-209
Author(s):  
Sylvie Polak-Charcon ◽  
Mehrdad Hekmati ◽  
Yehuda Ben Shaul
Keyword(s):  
Cell Line ◽  
Morphological Changes ◽  
Secretory Granules ◽  
Human Colon ◽  
Cell Types ◽  
Culture Conditions ◽  
Morphological Evidence ◽  
Human Colon Carcinoma Cell ◽  
Colon Cell

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).

scholarly journals Human cytomegalovirus transcriptome activity differs during replication in human fibroblast, epithelial and astrocyte cell lines

2012 ◽  
Vol 93 (5) ◽  
pp. 1046-1058 ◽  
Author(s):  
James C. Towler ◽  
Bahram Ebrahimi ◽  
Brian Lane ◽  
Andrew J. Davison ◽  
Derrick J. Dargan
Keyword(s):  
Gene Expression ◽  
Human Cytomegalovirus ◽  
Growth Kinetics ◽  
Viral Gene Expression ◽  
Cell Types ◽  
Viral Gene ◽  
Genome Replication ◽  
Cell Type ◽  
Low Passage ◽  
Temporal Expression Pattern

Broad cell tropism contributes to the pathogenesis of human cytomegalovirus (HCMV), but the extent to which cell type influences HCMV gene expression is unclear. A bespoke HCMV DNA microarray was used to monitor the transcriptome activity of the low passage Merlin strain of HCMV at 12, 24, 48 and 72 h post-infection, during a single round of replication in human fetal foreskin fibroblast cells (HFFF-2s), human retinal pigmented epithelial cells (RPE-1s) and human astrocytoma cells (U373MGs). In order to correlate transcriptome activity with concurrent biological responses, viral cytopathic effect, growth kinetics and genomic loads were examined in the three cell types. The temporal expression pattern of viral genes was broadly similar in HFFF-2s and RPE-1s, but dramatically different in U373MGs. Of the 165 known HCMV protein-coding genes, 41 and 48 were differentially regulated in RPE-1s and U373MGs, respectively, compared with HFFF-2s, and 22 of these were differentially regulated in both RPE-1s and U373MGs. In RPE-1s, all differentially regulated genes were downregulated, but, in U373MGs, some were down- and others upregulated. Differentially regulated genes were identified among the immediate-early, early, early late and true-late viral gene classes. Grouping of downregulated genes according to function at landmark stages of the replication cycle led to the identification of potential bottleneck stages (genome replication, virion assembly, and virion maturation and release) that may account for cell type-dependent viral growth kinetics. The possibility that cell type-specific differences in expressed cellular factors are responsible for modulation of viral gene expression is discussed.

Reversible disassembly of an intestinal epithelial monolayer by prolonged exposure to phorbol ester

1994 ◽  
Vol 266 (2) ◽  
pp. G214-G221 ◽  
Author(s):  
G. Hecht ◽  
B. Robinson ◽  
A. Koutsouris
Keyword(s):  
Tight Junction ◽  
Phorbol Ester ◽  
Barrier Function ◽  
Prolonged Exposure ◽  
Morphological Changes ◽  
Cell Types ◽  
Intestinal Epithelial ◽  
Epithelial Monolayer ◽  
Epithelial Barrier Function ◽  
Functional Changes

This article describes a model of reversible disassembly of a cultured human intestinal epithelial monolayer by prolonged exposure to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). Prolonged phorbol ester exposure reduces protein kinase C (PKC) levels in numerous cell types including T84, as shown here. Under PKC-downregulated conditions, T84 monolayers, which simulate the highly organized structure of native intestinal crypt cells, become disassembled into 2 or 3 layers of rounded cells. Proliferation does not account for these morphological changes as assessed by thymidine incorporation studies. The effects of structural disorganization on epithelial barrier function was also examined. The permeability of disassembled monolayers was significantly greater than that of controls. Flux studies localized the permeability defect to the tight junction. PKC-associated alterations in the perijunctional ring of actin and myosin, one of the putative regulators of flow across the tight junction, were found to correlate with the observed functional changes. Most interesting was the fact that monolayer reassembly to the original columnar epithelial phenotype and reestablishment of barrier function occurred upon normalization of PKC levels. This model of reversible monolayer disassembly will allow investigation into the relationship between epithelial structure and function and examination of factors that govern monolayer formation.

scholarly journals Meristem Development and its Relation to Endogenous GA3 and IAA Contents During Floral Bud Differentiation in Broccoli

2011 ◽  
Vol 35 (1) ◽  
pp. 1-6
Author(s):  
Xinmei Jiang ◽  
Xihong Yu ◽  
Dan Li
Keyword(s):  
Apical Meristem ◽  
Morphological Changes ◽  
Flower Bud ◽  
Bud Development ◽  
Meristem Development ◽  
Early Maturing ◽  
Initiation Stage ◽  
Academy Of Sciences ◽  
Bud Initiation ◽  
Floral Bud

The effects of three temperature treatments on morphological changes in the apical meristem and contents of GA3 and IAA in leaves during floral bud differentiation in early maturing cultivar of broccoli were studied. Plants went through every stage of flower-bud differentiation at day/night temperatures of 17.3±1/9.3±1°C. At 21.3±1/13.3±1°C, floral bud development ceased after primary axillary scape primordium differentiation and apical meristem entered a reversion stage. The apical meristem remained in the vegetative growth phase in plants growing at 25.3±1/17.3±1°C. Leaf GA3 contents started to increase while IAA contents started to decrease when plants entered the flower bud initiation stage. GA3 content was high and IAA content was low during all stages of axillary scape primordium differentiation.Key words: Meristem development; Broccoli; Apical meristem; GA3; IAADOI: http://dx.doi.org/10.3329/jbas.v35i1.7966 Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 1-6, 2011

scholarly journals Peroxide-induced membrane blebbing in endothelial cells associated with glutathione oxidation but not apoptosis

1999 ◽  
Vol 277 (1) ◽  
pp. C20-C28 ◽  
Author(s):  
Roosje M. A. van Gorp ◽  
Jos L. V. Broers ◽  
Chris P. M. Reutelingsperger ◽  
Nancy M. H. J. Bronnenberg ◽  
Gerard Hornstra ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Early Stage ◽  
Morphological Changes ◽  
Reductase Activity ◽  
Umbilical Vein ◽  
Cell Types ◽  
Surface Expression ◽  
Nuclear Condensation ◽  
Membrane Blebbing ◽  
Bleb Formation

Cells under oxidative stress induced by peroxides undergo functional and morphological changes, which often resemble those observed during apoptosis. Peroxides, however, also cause the oxidation of intracellular reduced glutathione (GSH). We investigated the relation between these peroxide-induced effects by using human umbilical vein endothelial cells (HUVEC) and two HUVEC-derived cell lines, ECRF24 and ECV304. With HUVEC, tert-butyl hydroperoxide ( tBH) or hydrogen peroxide application in the presence of serum induced, in a dose-dependent way, reorganization of the actin cytoskeleton, membrane blebbing, and nuclear condensation. These processes were accompanied by transient oxidation of GSH. With ECRF24 cells, this treatment resulted in less blebbing and a shorter period of GSH oxidation. However, repeated tBH addition increased the number of blebbing cells and prolonged the period of GSH oxidation. ECV304 cells were even more resistant to peroxide-induced bleb formation and GSH oxidation. Inhibition of glutathione reductase activity potentiated the peroxide-induced blebbing response in HUVEC and ECRF24 cells, but not in ECV304 cells. Neither membrane blebbing nor nuclear condensation in any of these cell types was due to apoptosis, as evidenced by the absence of surface expression of phosphatidylserine or fragmentation of DNA, even after prolonged incubations with tBH, although high tBH concentrations lead to nonapoptotic death. We conclude that, in endothelial cells, peroxide-induced cytoskeletal reorganization and bleb formation correlate with the degree of GSH oxidation but do not represent an early stage of the apoptotic process.

scholarly journals The Human c-Fes Tyrosine Kinase Binds Tubulin and Microtubules through Separate Domains and Promotes Microtubule Assembly

2004 ◽  
Vol 24 (21) ◽  
pp. 9351-9358 ◽  
Author(s):  
Charles E. Laurent ◽  
Frank J. Delfino ◽  
Haiyun Y. Cheng ◽  
Thomas E. Smithgall
Keyword(s):  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Morphological Changes ◽  
Neuronal Cells ◽  
Coiled Coil ◽  
Cell Types ◽  
Sh2 Domain ◽  
Microtubule Assembly

ABSTRACT The c-Fes protein-tyrosine kinase (Fes) has been implicated in the differentiation of vascular endothelial, myeloid hematopoietic, and neuronal cells, promoting substantial morphological changes in these cell types. The mechanism by which Fes promotes morphological aspects of cellular differentiation is unknown. Using COS-7 cells as a model system, we observed that Fes strongly colocalizes with microtubules in vivo when activated via coiled-coil mutation or by coexpression with an active Src family kinase. In contrast, wild-type Fes showed a diffuse cytoplasmic localization in this system, which correlated with undetectable kinase activity. Coimmunoprecipitation and immunofluorescence microscopy showed that the N-terminal Fes/CIP4 homology (FCH) domain is involved in Fes interaction with soluble unpolymerized tubulin. However, the FCH domain was not required for colocalization with polymerized microtubules in vivo. In contrast, a functional SH2 domain was essential for microtubule localization of Fes, consistent with the strong tyrosine phosphorylation of purified tubulin by Fes in vitro. Using a microtubule nucleation assay, we observed that purified c-Fes also catalyzed extensive tubulin polymerization in vitro. Taken together, these results identify c-Fes as a regulator of the tubulin cytoskeleton that may contribute to Fes-induced morphological changes in myeloid hematopoietic and neuronal cells.

Okadaic acid induces morphological changes, apoptosis and cell cycle alterations in different human cell types

2011 ◽  
Vol 13 (6) ◽  
pp. 1831 ◽  
Author(s):  
Vanessa Valdiglesias ◽  
Blanca Laffon ◽  
Eduardo Pásaro ◽  
Josefina Méndez
Keyword(s):  
Cell Cycle ◽  
Okadaic Acid ◽  
Human Cell ◽  
Morphological Changes ◽  
Cell Types ◽  
Cell Cycle Alterations
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